1. Field of the Invention
The invention relates to equipment for reclaiming, handling, and conveying from one area to another location bulk material which may be temporarily stored in piles or mounds in storage areas. Such bulk material can be of innumerable types and kinds such as coal, slag, Taconite, Pyrite or iron ore pellets, clay, cinders, crushed marble, gravel, pencil pitch, salt, agricultural lime, carbon black, sand, sawdust, wood chips, wheat, soy beans and other agricultural products, for example.
The bulk material is reclaimed from such storage piles and loaded onto railroad cars, trucks, conveyors, boats or other means of transporting the materials in desired quantities from a storage location to a place of use.
The invention relates more particularly to a rotary reclaimer wherein the reclaimer unit, operatively connected with transport or conveyor means, may be moved back and forth rectilinearly or arcuately in alternate reverse directions of unit travel to scoop up and discharge to the conveyor means bulk material, stored in large quantities in stacks in longitudinal or arcuate zones, during each of the two directions of reclaimer unit travel.
Further, the invention relates particularly to such a rotary reclaimer device which has a low cost of construction as compared with prior reclaimer devices, which easily may be installed as a part of existing bulk material handling systems, in which the reclaiming of bulk material during each direction of reclaimer unit travel assures efficient use of land where large quantities of bulk material may be stored, which is energy efficient in operation, and which handles bulk material without degradation.
2. Description of the Prior Art
During the last century many prior art patents have issued, for example U.S. Pat. Nos. 233,523 and 637,716, which show bulk material reclaimer devices wherein buckets are mounted on chains and move in one direction in an orbit of travel and scoop bulk material from a pile and discharge the bulk material to a conveyor or chute for transport to a desired location.
In all known prior chain mounted bucket devices the buckets move in one direction only in the orbit of bucket travel even though the support for the chain mounted buckets may be moved back and forth along a bulk material storage area in straight or arcuate directions. As a result, the buckets can only reclaim bulk material stacked in the storage area when the bucket support is moved only in one direction. Movement of the bucket support in the other direction only permits the storage area to be refilled by a stacker or other bulk material discharge means so that when the bucket support again moves in the one direction it can then reclaim material from the stack area.
Another known reclaimer device shown in U.S. Pat. No. 476,616 includes a boom which sweeps back and forth in an arcuate path. The boom comprises a trusslike structure which supports a paddlelike pusher chain conveyor moving in one direction from an outer end of the cantilever supported boom to the pivot center of the arcuate sweeping boom.
In the operation of this device the paddles are operative to push bulk material toward the boom pivot center as the boom swings or sweeps in either direction of arcuate movement. However, the paddles in conveying bulk material from the pile, move at right angles to the end of the pile as the boom moves toward that end of the pile, subjecting the cantilever mounted boom to great stress, thus requiring a heavy trusslike boom structure to resist such lateral stress and at the same time to support the lengthy chain mounted paddle pusher device.
Still another type of bulk material reclaimer is shown in U.S. Pat. Nos. 3,612,246 and 3,915,286. In each of these devices a series of scoops is formed as a part of a cylindrical wall of a rotary barrel which is moved along a path of travel so that the barrel as rotated bites into the end of a stack of bulk material.
In U.S. Pat. No. 3,612,246 the barrel has considerable axial length, is double walled with an annular compartment therebetween with which the scoops communicate to discharge reclaimed material from the annular compartment to an internal conveyor. This disclosure indicates that the barrel may be rotated in either direction and the scoops for multi-direction rotation are formed as opposite opening twin scoops. This construction is quite complicated and massive and requires considerable power to rotate the barrel as it bites into a stack of bulk material.
The device of U.S. Pat. No. 3,915,286 avoids some of these difficulties by using a barrel with a single series of integral scoops the lateral width of the scoops defining the axial length of the barrel. The rotating barrel rotates in one direction only and is moved axially back and forth along a massive movable support which straddles the storage stack of bulk material, so that the barrel traverses the end of the stack of bulk material being retrieved. Even though this variation in construction of rotary barrel has reduced barrel rotation power requirements, the physical size of the movable support structure to provide for axial barrel movement back and forth as it rotates requires a support structure which is massive.
Accordingly, a need has long existed for a simple bulk material reclaimer device wherein a series or set of buckets are pivotally mounted on a chain to move the buckets in an orbit of travel in either direction on and around a nonrotatable supporting cage with a plurality of sets of chain mounted buckets located axially adjacent one another throughout the length of the supporting cage, and in which the supporting cage may be moved back and forth either rectilinearly or arcuately in paths of travel to retrieve bulk material from stacks thereof with efficiency in energy and storage area utilization.